In high-temperature gas-cooled reactors (HTGRs), accumulated fission products in the primary circuit may be released into the environment during accidents, such as loss-of-coolant or water-ingress events, contributing to the source term. Among the radioactive species, iodine is a major constituent with significant environmental and human health impacts Pool scrubbing is an effective method for iodine removal, as gaseous products passing through the pool are retained. In HTGRs, the carrier gas is non-condensable, which influences the scrubbing process, as the absence of steam condensation—unlike in light water reactors (LWRs), where steam condensation enhances retention—reduces retention efficiency. In this work, we experimentally investigate the decontamination effect of pool scrubbing for iodine carried by non-condensable gas. A mixture of Na2S2O3 and NaOH solution is used as an absorber for iodine. The concentration of elemental iodine is quantified using an ion-selective electrode (ISE), and the decontamination factor (DF) is defined as the ratio of iodine concentration at the inlet to that at the outlet. The results indicate that iodine removal efficiency depends on the inlet iodine concentration and submergence depth. As the iodine concentration increases, the DF also increases. Additionally, greater submergence depth extends bubble retention time, leading to higher DF values.